A kinetic flow machine such as a radial turbocompressor is configured, for example, as a single shaft compressor which has a shaft, with running wheels threaded onto it, and a housing which surrounds the running wheels. The shaft is mounted radially and axially outside the housing by means of bearings, flow channels from and to the running wheels being formed in the interior of the housing by the provision of housing internals. The running wheels are configured, for example, as radial running wheels which have, for example, an axial inflow direction and a radial outflow direction. Flow passes through the running wheels one after another, with the result that process gas is compressed in stages from running wheel to running wheel. An annular diffuser is provided on the outflow side of each running wheel, through which annular diffuser the process gas is guided radially to the outside. The process gas is deflected with the aid of a deflection channel after the annular diffuser, and is guided radially to the inside again through a return channel to the next running wheel. In the housing, the housing internals are provided with a corresponding shape, with the result that the annular diffuser, the deflection channel and the return channel are formed by the interaction of the housing internals in the housing.
The housing internals are conventionally configured as intermediate housing floors. Each intermediate housing floor is formed by two halves, with the result that the intermediate housing floor can be divided horizontally. Thus, for example, an intermediate housing floor can be mounted by attaching one half into the lower part of the housing (horizontally divided fluid kinetic machine) or into the lower part of the inner housing (vertically divided fluid kinetic machine) and by fastening the other half into the upper part. The two halves form a part joint at their contact faces, which part joint can gape apart on account of production inaccuracies and/or a deformation of the halves caused by pressure loading during operation of the radial turbocompressor, and can therefore become gas-permeable. As a result, a leak is produced through the part joint, which leak is considerable, in particular, in the case of radial turbocompressors with high pressure differences. In particular, the leak is disadvantageous in the case of radial turbocompressors with a high pressure ratio and a small delivery volumetric flow. The degree of efficiency of the radial turbocompressor is reduced by the leak, as a result of which the required input power is increased if predefined boundary conditions are met by the radial turbocompressor. Furthermore, the maximum possible prediction accuracy with regard to pressure ratio and delivery volumetric flow of the radial turbocompressor is affected by relatively high tolerances, since the actual effect of the possibly gaping part joint on the operating parameters of the radial turbocompressor can be predicted only with difficulty.
Here, for example, the provision of an O-ring in the part joint could provide a remedy. However, there is the disadvantage here that the O-ring can be destroyed in the case of a relative movement of the halves of the intermediate housing floor. O-rings are likewise not suitable for all thermal and chemical loads. It would also be conceivable in the part joint to provide the halves of the intermediate housing floor with grooves, into which a feather key is arranged. The locating fits necessary for this purpose for inserting the feather key into the grooves cannot be maintained, or can only be maintained to a limited extent, in a manner conditional on manufacturing. As a result, clearances are set between the feather key and the grooves, which clearances form a connecting channel between the two sides of the intermediate housing floor, with the result that the leak through the part joint would be increased disadvantageously.